Improvement in coffer-dams



aient attire,

JOHN E. WALSH, OF NEW YORK, N. Y@

' Letters Patent No. 113,374, dated April 4, 1871.

IMPROVEMENT IN COFFER-DAMS.

The .teheule referred to in these Letters Patent and making part of thesame.

I, J OHN E. WALsH, of the city, county, and State of New York, haveinvented certain Improvements in Coffer-Dams, of which the following isa specification;

As coder-dams are generally constructed they are only intended to beused as arneans of'proteeting workmen and their work from the presenceof water or mudin building piersor abutments-ef masonry, and whollysurrounding the m-asonry to be 4built within them.

'lhe object of this invention is to so construct a coifer-dam as that acontinuouswall of masonry may be built, and the coiffer-dam moved alongin advance of the wall as it is built, and afford all the necessary orneeded protection that the ord'inary cofi'er-dam could while masonry isbeing built withint it; and

It consists in the construction of the wallsof the dam so that after onesection of what is to be a continuous wall is built within thecoffer-dam, the dam can then be moved forward in the line at which thewall is to be built, and by devices bc clamped fast to the wall that iscompleted so that another section of wall of the length of the inside ofthe dam can be built and joined upon that iirst collstructed.

In the drawing- Figure l is a top view of the coder-darn with a sectionof a wall built inside ot' it;

Figure 2 is a side view of the dam and Figure 3 is a top view of the damand section of a wall after the dam has becnadvaneed for building asecond section ofthe wall.

ln the construction oi' the eoffer-dam the side wallsV and forward end,and thc'dcvices for holding the dam in its position, are the ,same asshown in a patent granted to me, numbered 111,157; and the improvementsto be described relate to the construction of the rear wall of vthe dam,and its adaptability to be attached to the wall when built.

A represent-s the curved side walls of the dam, which may be of anyrequired length or height;v

B- is the .rear or back end wall, extending from each side toward thecenter, of 4the width of the dam, lbut leaving a space, O, in the centera little wider than the wall to be built is thick, and, for the purposeof greater strength, is made double and with compartmentsB'.

At the inner sides of the two Ainner compartments theA inner wall-plateC, on each side of the center, turns a right angle and forms the insidewallstofthe two interior compartments next the open Vspace O, andextends back and in the rear of the wall B so as to forn a iiange, G, ofsufeient width to be clamped against the wall when necessary.

To the cxtreme back-edge of ang'es O' are hinged curved doors a, and atthe junction of the doors with the flanges, and attached .to the doors,are angle-plates c, with packing d interposed betweenvthe plate and doorand between -the plate and flange-plate C', so that, when the doors areclosed against the packing c between them, at' their extreme rear ends,and bolted together, as seen 'in fig. 1, all the joints will bewatertight in the same manner byangle-plates and packing;

The compartments B may or may not have bottoms,

v'as fancy orwant may dictate.

'lhc doors'a, at the rear end oi' thc dam, are hinged insuch way thatthey canbe raised off of their hinges and be detached from the flangea.Y

The operation of building aA wall by the use of this coffer-dam is asfollows: i

The Cotter-dam, as seen in iig. l, is taken-to the precise spot wherethe wall is to be built, sunk, and secured in itsposition in the usualway, the water pumped out and the foundation prepared; then the wall Dis built, as seen in said iig. 1,thc entire length of the inside of thedam; this d'one, the doors a. are removed from the flangesV G. Theco`er-dam is then moved forward and planted, as seen in iig. 3with theforward end of the wall between the flanges C'.

As the wall D is being built there are anchored and built in thewallymetal eyes or staples E, and extending the proper distance from eachside oi' the wall and at a suitable distance from the forward end ofsaid l wall, as seen in iig, v1 to receive the bottoni ends of theclamp-piles F.

Between the iianges C and the wall D is placed a thick packing-sheet, d,when the 'clamp-piles F are forced at their bottom or lower ends intothe eyes or staples E, brought toward each other at their top ends, andbearing hard against the iianges 1U their entire length, when theel-ampf, having the two eyes, is placed around them, and securely holds thecutter-dam water-tight `upon the wall, when the water is again taken outof the dam and the wail can be extended the length of the inside of thedam, and so continue the successive changes until the desired length ofwall` is completed., Curved, or walls with angles, can be built withthis construction of dam as well as straight ones.

The double walls B being hinged -to the side walls, they 'ca-u be, whennecessary, opened, which will allow ot' the successful turning ot thedam where angles or curves are built in the wa1l,.and may facilitate thehandling and moving the dam at other times.

Such 'construction oi' coffer-dam haslong been needed, and will be avaluable acquisition wherever Vsea or continuous walls are to be built.

Having described my invention, l

`Wlmt I claim, and desire to secure by Letters Patent, is- 1 l. The@offer-dam herein described', having a, double wail, B, at its rear end,with openingr O, nnges C', and removable doors a, constructed andarranged in the manner and for tire purpose set forth.

2. The flanges Of of the cofer-dnm herein' described,4

'in combination with the interposed packing d, metal eyes or stnpies E,clamppiles F, and chimp f.' constructed and arranged in the manner :mdfor the pnr pose described.

JOHN E. WALSH. Witnesses:

WILLIAM A..HOYT, GEO. A. BLACK.

